1. Field of the Invention
This invention relates to a method and apparatus for the control and exchange of the atmosphere surrounding materials to be treated.
2. Background and Prior Art
In the thermal processing of materials, especially various electronic components, by treatment with various reactive gases in high temperature furnaces, it is often necessary to purge the materials and their environment of gases, such as air, that may produce adverse reactions in the high temperature conditions of the furnace. To this end, various exhaust systems, scavenger chambers, and the like, have been designed for the purging of the materials prior to entry into the furnace or within the furnace, generally near the entry section of the furnace.
U.S. Pat. No. 4,992,044 to Phillipossian discloses a furnace for high temperature treatment of semiconductor wafers utilizing a scavenger arrangement for controlling gas flow.
U.S. Pat. No. 5,118,286 to Sarin discloses a method and apparatus for controlling gas flow patterns and avoiding the mixing of spent reactant gases with ambient air in the treatment of semiconductor wafers.
U.S. Pat. No. 5,645,417 to Smith discloses a thermal treatment of silicon wafers in a thermal processing furnace tube wherein the inner surface has a plurality of dimples thereon to promote a more turbulent flow of gases and a more uniform reaction across the surface of the wafers.